1. Field of the Invention
The present invention relates to an apparatus for assorting articles according to size, and more particularly to such an apparatus for use in sorting fruit and other agricultural produce accurately and rapidly into a plurality of sizes without damaging the articles.
2. Description of the Prior Art
In marketing agricultural produce, such as fruits, which grow in a relatively wide range of sizes, it is customary to assort the fruits by size into categories for marketing. The number of categories and the dimensional range in each category vary widely according to the type of fruit, the premium paid for larger sizes, marketing regulations, and the like.
Manual assorting of produce by size is both slow and highly inaccurate; therefore, machines for such assorting have long been well known. Prior art produce assorting machines typically utilize openings dimensioned sequentially as to size in a generally planar member over which the produce passes, articles smaller than the smallest dimension of each opening being assorted by falling through the opening. As produce to be assorted moves over the openings and the member, individual articles thereof are tumbled by contact with the member, and this tumbling damages the articles by contact with other articles and with the member. The assorting of produce by machines utilizing openings graduated in size through which articles fall is also deficient in that the resulting accuracy, although superior to hand sorting, leaves a great deal to be desired. Further, such assorting of articles which are not generally spherical results in relatively inaccurate sorting since the attitude at which each article arrives at an opening is unpredictable and, in any event, varies as the article tumbles along the planar member.
Another disadvantage of such prior art machines is that an opening of a given dimension can assort articles not larger than one size so that it is not possible to vary the range of sizes in each category even, as with substantially spherical articles of produce, it is possible for an opening to discriminate between articles of relatively limited differences in diameter.
A further disadvantage of many prior art machines for assorting produce is that a substantial amount of time is required to modify the machine for assorting fruits into categories of different sizes, since the members providing the sorting openings must be replaced or, at least, repositioned, and it is necessary to shut down the machine while the members are converted. Thus, most known assorting machines are limited to only one type or one kind of fruit each day because of the down time for conversion. It has long been considered highly desirable to provide an assorting machine which is convertible almost instantly to different types, sizes, shapes, and varieties of fruit.